A JetBlue Airways captain has been charged with interfering with a flight crew after he sprinted down the cabin of a flight screaming about a bomb.

An affidavit states that captain Clayton Osbon told his co-pilots that "things don't matter" during a Las Vegas-bound flight on Tuesday. Osbon then told the plane's first officer that "we're not going to Vegas" and began giving a sermon.

Four men managed to restrain Osbon, using seatbelt extenders and zip-tie handcuffs to pin him to the floor for more than 20 minutes while the co-captain and an off-duty pilot made an emergency landing in Amarillo, Texas.

Passengers realised something was wrong when the pilot walked out of the cockpit and attempted to force his way into an occupied bathroom. Colleagues tried to calm him down as he became more jittery, coaxing him to the back of the plane while ensuring he did not get near the plane's controls. But he broke free and sprinted up the aisle, claiming there was a bomb. Passengers said Olson urged them to pray and shouted, "They're going to take us down."

"Nobody knew what to do because he is the captain of the plane," said Don Davis, who was aboard the plane at the time. "You're not just going to jump up and attack the captain."

Tony Antolino, who sat in the 10th row and tackled Osbon when he attempted to re-enter the cockpit, said: "Clearly the pilot had an emotional or mental breakdown. He became almost delusional."

Fellow passenger Josh Redick said Osbon seemed "irate" and was "spouting off about Afghanistan and souls and al-Qaida".